Apparatus for determining the spherical luminous intensity of light sources



May 11 ,1926. 1,584,650

v H. M. H. REUFEL APPARATUS FOR DETERMINING THE SPHERIAL LUMINOUS INTNSITY OF LIGHT SOURCES Filed April 18, 1924 2 Sheets-Sheet 1 Heinrich M. H.`Reu"el,

His Att orrwey.

May l1 1926. 1,584,650

H. M. H. REUFEL.

APPARATUS FOR DETERMINING THE SPHERIGAL LUMINOUS INTENSITY OF LIGHT SOURCES Filed April 18, 1924 2 Sheets-Sheet 2 Inventor: Heinrich M. H. ReuFel,

H is Attorney.

release aia-y ii, iaae. $534965 ELECTRIC COMPANY, A CGBPGRATION OF NEW' YBK.

APPARATUS FOR DETERMNING THE SJEERICAL LUMI-NOS INTENSTY OF LIGHT SOURCES. f

Application led April 18, 1924. Serial No. 707,464.

This invention relates to improvements in source, the intensity of which has been 55 apparatus for ascertaining by means of a measured may be removed from one of the sphere photometer the spherical luminous other two portions and a new source of light intensity of light sources and more particuhe located in the third portion.

larly of electric lamps. rEhe apparatus according to the present In the manufacture of electric lamps it invention is particularly adapted for meas- 60 frequently occurs that the luminous intensity uringthe spherical luminous intensity of of the finished product must be inspected electric lamps.v rll`he lamps are, for cnamand it is therefore of greatvimportance that ple, suspended by means of their leading-in this inspection should be promptly and wires in the rotary portionsof the sphere easily effected. photometer. In this case preferably each of U5 It is known to measure the spherical luthe spherical portions that are rotatable in minous intensity of a light source by means common contains a device for suspending a of a sphere Photometer. rIhe light source is lamp, said device also serving for the suplocated within a sphere having a diffusing ply of current, electric contacts being so n inner surface which reccts the light and mounted that a lamp is supplied with curhas a window for example of inillr glass, a rent in that position of a rotary portion in screenbeing provided betweenthe window which it is measured, whereas in the other and the light source to prevent the window positions the suspension device cannot be from being struck by 'direct rays. rlhe lusupplied with current.

minous intensity of the window is measured ln the positions in which no measurement 75 by any known means, said intensity being a is effected, it is consequently not dangerous measure of the spherical luminous intensity to touch the suspension device by hand. To of the light source. ln the apparatus acthe central shaft, to which the portions of the cording to the present invention, the spherisphere are secured and around which they cal surface of the sphere photoineter has a are rotatable in common, a table may be sestationary portion in which the window is cured on which for each spherical portion is provided, and a remaining rotatable por mounted a set of current supply contacts cotion, to which the device for holding the operating with one set of stationary contacts. 30 light source is secured. lf the apparatus according to the present The screen that serves to prevent a direct invention is intended for measuring the luillumination of the window by the source of minous intensity of electric lamps, it is pref- 4light is preferably secured to the stationary' erably provided for each of the spherical portion of the spherical surface. portions which are rotatable on the central By moving the rotary portion of the shaft with a set of,voltmeter-contacts male spherical surface into a predetermined posiing Contact in the position in which the 5U tion, the light source can be easily put into luminosity is measured with one set of staplace in the said apparatus and' by moving tionary contacts. said rotary portion into the position in The accompanying drawing diagrainmati- 40 which a closed spherical surface is formed, cally illustrates an apparatus embodying the the luminous intensity can be measured, present invention. ln the said drawing: 9U 'whereupcn the movable portion can be Figure l is a view and partly a vertical moved into a position, in which the light section of an apparatus for measuring the source can be easily removed; a further iinluminous intensity of electric lamps, said portant simplification is introduced if a apparatus comprising three rotary spherical number of portions of a sphere are rotatportions. -100 able around a common vertical central shaft Figure 2 is a horizontal section taken' on so that each portion is capable of succesthe line A-B of -Figure l, and sively forming a closed spherical surface Figure 3 is a view on a large scale of the with the stationary portion. uppermost part' of the. apparatus with the if, for example, three rotary portions are various electric contacts, showing also the 105 provided, one of them may be moved into accessory circuit arrangement. i the position in which the source of light is The apparatus shown on the drawing measured, and simultaneously the light comprises a vertical column 1 carrying a Cil verti 'al post S, on which a toiunn 'i is :otatablc, said colunui resting cn the column i bv means ot a ball-bearing 5 To the column :l is connected a housing` l in which three portions ot' a sphere 5, 6 and T arc mounted, and on a table 9 at the top end ot the said column are p 'ovided several contacts 'tor the supply ot' current and tor the roltnietcr.

yEhe stationary part of the sphere photonieter is secured to tivo vvrtical columns and ll. 'the stationary part ot' the spherical surface l2 is cons quentiv also linie-cl to thcm, and is provided with a Window consisting 'tor exaiiole ot millt glass. The uniinous intensity ot this windenv is measured b v known means not shown on the d airing- A screen l-l is suspended by means ot bolts l5 on the stationar)Y part l2 and arranged betvreen a light source and the Window 13 in order to prevent direct illumination ot the latter.

table 1G seiwingar tor carrvvin the stationaiv electric contacts ot' the ..ppzxatus is tired by means ot' nuts to the top end of the vertical shaft 8 and t the columns ln the apparatus shown on the drawing, the table 9 is provided with a set otl current supply contacts and a set ot voltmeter contacts 1for cach lamp, and a set ot current suppl)v contacts as Well as a set ot voltnieter contacts tizied to the table lo.

During` the rotation ot the central post 2 with the housing +1, the contacts engage each other successively so that current is supplied to a lamp in the position in which ct current. l

(En the bottoni side the contacts 2O and 2l carry esllient contact pieces Q2 and Q3 consisting ot sonic suitable material, YFor eX- iniplr` ot' carbon or ot a liighllv.' retractorv such as tungsten.

ln the position in which the apiaratus is shown on the drawing, the contact. pieces 2:2 and engage' contacts and 25 mounted on tlierotary table 9. To these contacts wires Q5 and 27 are connected which lead through a tube 2S to the suspension device. for the lamp. rllhe tube 28 is vertically movable so as to permit of its position bcing adjusted according to the dimensions of the lamps und r test, and can bc held in any position by i'ieans of a clanu'iing-screw 3l. The tube 2S carries t its bottom end :i .smell table to' rhieli' clamps 35' 6 a an d tor the lamp are lifted. The lading-in Wires "for a lamp 3T arc susiendcd bctvfeen the piece" *e and lo and plates 35 and S) which are icsilienil",v liept cn 'age l.

@n the table lo are alsi prorided two v"Vineter contacts ll and l2 to which con tarts and tl are i'xcd tifnilar suspension devices, as for the lamp 3:. e provided in the Yivo other rotary spherical por ions. The various wires for he suspension devices pass through vertical libcs 2) and Ill) which can be held in posiion b v means ot clamping screws 32.

The. operation ot' the apparatus according lo the invention brief;v as t'olloivs:

.lamp is suspended in one ol the rotary io is ot' the spherical surlacc. The post 'otated bj; hand until the portion under conside ation toi-ins a closed spherical surtfce vwith the stationar)vv part lzf, e., in the ition in which the portion (i is shown on the dra ri i this position the rotatable current supply contacts engage the stationarv contacts 2O and 2l, u'herebuv the ilanent ol the lamp is lighted so that l luminous intensitav ot' thc lamp can bc it the saine time the strength of n'rent is read on the ampereineter A nd ie voltage ot the lainp on the voltincter so that both the luminous intensity and nsuinption ot energy of the lamp are r aincd. vWhile the measurement is caron, a nciv lamp suspended in another i irtion, tor example, in the portion 7. ne ineasuren'ient is h'nished, the post 'l into a further position, the port ig thus replaced by the portion 7. v'hilst the luminous intensit;v ot the lamp ici i icasured in the portion 7, the lamp in the portion 5 is removed and a new lamp is located in the portion (i.

is, oll courser` obvious that the rotary is prorided with sonic suitable means lo permit ol' its beineY moved into and loel ed iu each acti 'e position. il resilient paivl `which enters into a slot inauv serve for this purpose. It is also obvious that the rotatif,T part instead of b v hand, can also be diven niechaiicallv in soine suitable manner.

TThat l claiin as new and desire to se 'ure by Letters Patent of the United States, is,-

l. Ei device for measuringT the spherical luminous intensity of a light source coinprising a photonicter,r said pliotorietei coinlt purl prising in turn a stationary section of a chamber and a series of chamber portions all mounted on a shaft to rotate about a common axis so that each portion is capable of successively formingy With the stationary portion a spherical photometer closur y.

2. A device for measuring the spherical luminous intensity oiC a light source comprising a photometer, said photometer coinprising in turn a stationary spherical portion, a series oit other spherical portions all mounted on a common shaft to rotate about a common axis so that each portion is capable oft successively forming with the Stationary portion a. photometric sphere, a holder associated with each rotatable portion ifor supporting a light source, each holder so located that when the corresponding rotatab'e portion forms a sphere With the. stationary portion the light source in the corresponding holder stands in the measuring position, and electric contacts mounted tor supplying current to each lamp in the a light source, each holder so located that when the corresponding rotatable portion forms a sphere with a stationary portion the light source in the holder stands in the measuring position, electric contacts sup-ported to rotate with said shaft tor supplying current to each lamp in the measuring position and to prevent the supply of current thereto when in some other position, said contacts being adapted to cooperate With a set ofstationary contacts.

d. A device for measuring the spherical luminous intensity of a light source comprising a photometer, said photometer comprising in turn a stationary spherical portion, a series of other spherical portions all mounted on a common shaft to rotate about a common axis so that each portion is capable of successively forn'ling with the stationary portion a substantially closed sphere, a lamp socket associated with each rotatable portion ttor supporting a light source, each socket so located that When the corresponding rotatable portion forms a sphere With a stationary portion the light source in the` socket stands in the measuring position, and electric contacts supported to rotate with said shaft, and a cooperating set ot' stationary contacts for measuring the Voltage of the light source when the light source is in the measuring position only.

In Witness whereof, I have hereunto set my hand this eighteenth day of March, 19:24.

HEINRICH M. H. REUFEL. 

